As it stands right now, the GPS capabilities of the iPhone can only be used by active applications. This prohibits the iPhone from being used as a geotagging assistant or tracking device. However, Apple may be working on functionality for the iPhone that can track your location in the background. A hint that this functionality may be in the works comes from iPhoto ’09, which shows traces of being able to associate such GPS log data with photos.
By logging your location in the background, the iPhone could provide geotagging information that could be associated with pictures taken with a different camera. Alternatively, the information could be used to show a map of your travels.
Sources say an unused nib file in iPhoto could be evidence of this possible feature. As you can see from the screenshot below, the application assumes there’s a location application on the iPhone (or iPod Touch) that could track your moves and transfer location data to iPhoto.
There’s also a string in the iPhoto binary that appears to provide the iPhoto side of the directions. It reads, “Select an iPhone or iPod Touch from your list of named devices. Once selected, the appropriate information will be transferred to your iPhoto library and associated with the photos in the selected event(s).”
This evidence doesn’t make anything official, however. The feature is not functional in iPhoto ’09. There’s also no known location application in the iPhone with which you can connect.
In the end, there’s no guarantee Apple will add additional location-based data to be used with iPhoto’s geotagging feature, but the evidence certainly makes you wonder what Apple is considering.